SB2025120949 - Multiple vulnerabilities in Microsoft Exchange Server

Description

This security bulletin contains information about 2 vulnerabilities.

1) Input validation error (CVE-ID: CVE-2025-64666)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote user to escalate privileges within the application.

The vulnerability exists due to insufficient validation of user-supplied input. A remote user can send a specially crafted request to the mail server and gain administrator privileges.

2) Spoofing attack (CVE-ID: CVE-2025-64667)

CWE-ID: CWE-451 - User Interface (UI) Misrepresentation of Critical Information (Clickjacking, spoofing)

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to incorrect processing of user-supplied data. A remote attacker can spoof an 5322.From email address that is displayed to a user.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-64666
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-64667